Pro tip: the cross ventilation trick saved me 2 hours on a drying job

Last week I was finishing up a basement remodel and the paint was taking forever to dry because of the humidity. A buddy who does disaster restoration told me to open windows on opposite sides of the house and put a box fan in one of them pointing out. I thought he was crazy, but I tried it on a job in Fargo. Within 45 minutes the air was moving so fast the paint was dry to the touch. I usually just open one window and hope for the best, but this cross flow thing actually works way better. Has anyone else tried this for speeding up dry times on paint or mud?

3 comments

3 Comments

the_riley21d agoTop Commenter

Honestly a buddy of mine tried the fan-pointing-out thing on his own house and ended up with negative pressure so bad it sucked dust from the attic into his fresh paint. He said the whole room looked like it had a layer of sand on it by morning.

the_max21d ago

Ha, I hate to be that guy but the fan should be pointing in, not out. You want it pulling fresh air from the other window and pushing it through the room. Pointing it out just sucks the air out and creates negative pressure, which can actually pull humid air from the rest of the house into that room. I learned that the hard way when my drywall mud started cracking because the air was too dry from the fan fighting itself.

davis.noah19d ago

Haha, "negative pressure so bad it sucked dust from the attic" - that's rough, buddy. I did something similar once but with a box fan pointed OUT of a basement window and it actually pulled a dead mouse out from behind the wall (not kidding). The max is right though, I finally learned the trick after ruining a bedroom ceiling - pointing the fan IN and opening a window on the far side creates this nice gentle breeze instead of a tornado. I still manage to mess it up half the time though, usually by accidentally closing the intake window while the fan is running and creating a weird vacuum that slams doors shut.